The importance of Clubroot resistance

Murray Forsyth is a mixed arable-beef farmer with a total area of 1000 acres in Inverurie, Aberdeenshire. He grows around 170-180 acres of OSR dependant on year and rotation. The current rotation includes winter barley, OSR, winter wheat and 2 spring barleys.

When clubroot first appeared on farm he adopted a wider 5-year rotation, as well as choosing a clubroot resistant variety for afflicted fields.

To keep his crop yielding and profitable, Mr Forsyth takes a technical approach to growing OSR. He has good average to medium soil type and a scheduled soil testing programme on his farm. He aims to keep the value around 6.2, by applying lime to the fields that have a lower pH; he also applies FYM to his fields to keep fertility high.

In terms of cultivation, Mr Forsyth typically ploughs the field before drilling his OSR. He uses a Horsch Express combination drill with DAP as fertiliser (down the spout -around 200 kg/ha) followed by a Cambridge roll. He spreads slug pellets as a precautionary tactic since slugs are a bigger problem than the flea beetle in his area.

Mr. Forsyth’s average OSR yields are between 1.7 and 2 tonnes/acre. In fields affected by clubroot he is growing LG Anarion. He mentions the average yield is in line with the rest of the farm, which is currently LG Armada. He is convinced that varietal choice is keeping his yields at the same levels as the fields unaffected by clubroot.

Mr Forsyth is considering going back to a shorter 4-year rotation, as OSR remains one of the most profitable crops on farm. He records his yields and profits margins across the years, Mr Forsyth notes that OSR is not the cheapest crop to grow, however it remains a very profitable break crop. Maximising acreage for this crop and maintaining a decent yield are key to its success on farm.

Murray Forsyth, Smiddyburn Farm, Inverurie, Aderdeenshire

Using a clubroot resistant variety such as LG Anarion really helps OSR remain as a crucial part of the farm’s rotation, allowing OSR to be grown in fields affected by high clubroot pressure. LG Anarion will also help alleviate the pressure as resistance does not allow clubroot spores to multiply.